Measuring device and measuring method

ABSTRACT

A measuring device is a measuring device that performs colorimetry of an evaluation patch formed on a medium and a paper white patch that is a portion exposed by the medium. The measuring device has a light source portion that irradiates the medium with an illumination light, a measurement portion that acquires an amount of light from the medium as a measurement value, a memory that holds a paper white standard value that is a reference measurement value of the paper white patch, and a colorimetry unit that corrects a measurement value of the evaluation patch based on the measurement value of the paper white patch and the paper white standard value. Even in a case where a measurement position is changed, a reflectance of the evaluation patch is accurately calculated and a chromaticity of the evaluation patch can be accurately acquired.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/714,016, filed on Sep. 25, 2017, which claims priority to JapanesePatent Application No. 2016-190768 filed on Sep. 29, 2016, thedisclosures of which are hereby expressly incorporated by referenceherein in their entireties.

BACKGROUND 1. Technical Field

The present invention relates to a measuring device and a measuringmethod of the measuring device.

2. Related Art

In the related art, in an image forming apparatus such as a printer,there is known an apparatus including a measuring device that measures acolor of a measuring object (for example, see JP-A-2005-59552).

An apparatus described in JP-A-2005-59552 includes a light source thatirradiates illumination light to the measuring object and measures lightreflected by the light source using a measuring device. In the apparatusdescribed in JP-A-2005-59552, a focal position of the illumination lightis set behind (side opposite to the measuring device) the measuringobject. In this case, even in a case where undulation (cockling) or thelike occurs due to, for example, an influence of humidity ortemperature, or an action of a physical external force, an amount ofchange in light intensity of the light received by the measuring deviceis reduced and it is possible to suppress reduction of measurementaccuracy.

Meanwhile, usually, in a case where colorimetry is performed by themeasuring device, the colorimetry is performed according to geometricconditions defined by a colorimetric standard (JIS Z 8722), that is, themeasuring object is irradiated with the illumination light at 45 degreesand a reflected light reflected at 90 degrees is measured by themeasuring device (45/0° colorimetric system), or the measuring object isirradiated with the illumination light at 90 degrees and the reflectedlight reflected by 45 degrees is measured by the measuring device (0/45°colorimetric system).

However, for example, in a case where cockling or the like occurs in themeasuring object and a position of the measuring object is changed, adistance between the measuring object, the measuring device, and thelight source is changed, and a position of an illumination region wherethe measuring object is irradiated with the illumination light or ameasuring region which is capable of being measured by the measuringdevice is changed. Therefore, an amount of the illumination light in anoverlapping portion between the measuring region and the illuminationregion is changed. Therefore, there is a problem that the amount of themeasuring light incident on the measuring device is also changed and itis difficult to perform colorimetry with high accuracy.

SUMMARY

An advantage of some aspects of the invention is to solve at least apart of the problems described above, and the invention can beimplemented as the following forms or application examples.

A measuring device according to an aspect of the invention is ameasuring device that measures colors of an evaluation patch formed in ameasuring object and a paper white patch which is a portion exposed bythe measuring object, the device including a light source thatirradiates the measuring object with an illumination light; ameasurement portion that acquires an amount of light from the measuringobject as a measurement value; a storage portion that holds a paperwhite standard value that is a reference measurement value of the paperwhite patch; and a correction portion that corrects a measurement valueof the evaluation patch based on a measurement value of the paper whitepatch and the paper white standard value.

APPLICATION EXAMPLE 1

A measuring device according to this application example is a measuringdevice that measures colors of an evaluation patch formed in a measuringobject and a paper white patch which is a portion exposed by themeasuring object, the device including a light source that irradiatesthe measuring object with an illumination light; a measurement portionthat acquires an amount of a reflected light which is acquired byreflecting the illumination light by the measuring object as ameasurement value; a storage portion that holds a paper white standardvalue that is a reference measurement value of the paper white patch;and a correction portion that corrects a measurement value of theevaluation patch based on a measurement value of the paper white patchand the paper white standard value.

For example, in a case where cockling or the like occurs in themeasuring object and a distance between the light source, themeasurement portion, and the evaluation patch, that is, a position(hereinafter, referred to as a measurement position of the evaluationpatch) of the evaluation patch with respect to the light source and themeasurement portion is changed, the amount (hereinafter, referred to asan amount of received light) of the illumination light with which themeasuring object is irradiated is changed and it is difficult to performcolorimetry with high accuracy.

If the paper white patch is disposed close to the evaluation patch andthe position (hereinafter, referred to as a measurement position of thepaper white patch) of the paper white patch with respect to the lightsource and the measurement portion, and the measurement position of theevaluation patch are made the same, the amount of the received light isthe same for the paper white patch and the evaluation patch, and adifference in the amount of received light in a case where themeasurement position is changed is the same for the evaluation patch andthe paper white patch. Therefore, if the measurement value of theevaluation patch is corrected by the difference in the amount ofreceived light of the paper white patch in a case where the measurementposition is changed, an influence of the difference in the amount ofreceived light of the evaluation patch in a case where the measurementposition is changed is reduced and it is possible to perform colorimetrywith high accuracy.

For example, the difference in the amount of received light of the paperwhite patch in a case where the measurement position is changed can berepresented by a colorimetric result (measurement value of the paperwhite patch) of the paper white patch in the measurement position and acolorimetric value of a reference medium (for example, a standard whiteplate) in a reference measurement position. However, if the measurementvalue of the evaluation patch is corrected by the measurement value ofthe paper white patch and the colorimetric value of the referencemedium, a difference in color tone between the paper white patch (thatis, the measuring object) and the reference medium is affected and it isdifficult to properly correct the evaluation patch.

On the other hand, if the difference in the amount of received light ofthe paper white patch in a case where the measurement position ischanged is represented only by the paper white patch, it is possible tocorrect the measurement value of the evaluation patch without receivingthe influence of the color tone of the paper white patch (that is, themeasuring object). Specifically, if the difference in the amount ofreceived light of the paper white patch in a case where the measurementposition is changed is represented by the colorimetric result(measurement value of the paper white patch) of the paper white patch inthe measurement position and the measurement value (paper white standardvalue) of the paper white patch in the reference measurement position,and the measurement value of the evaluation patch is corrected by themeasurement value of the paper white patch and the paper white standardvalue, there is no influence of the color tone of the paper white patchand it is possible to properly correct the evaluation patch.

Therefore, the correction portion corrects the measurement value of theevaluation patch based on the measurement value of the paper white patchand the paper white standard value so that the influence of a case wherethe measurement position of the evaluation patch is changed is reduced,and, for example, even in a case where the measurement position of theevaluation patch is changed by cockling or the like in the measuringobject, it is possible to perform colorimetry with high accuracy.

APPLICATION EXAMPLE 2

In the measuring device according to the application example, it ispreferable that the measuring device further includes a standard whiteplate, the storage portion further holds a standard white value that isa reference measurement value of the standard white plate, and thecorrection portion corrects a measurement value of the evaluation patchbased on a measurement value of the standard white plate and thestandard white value.

For example, if the light source or the measurement portion changes withtime, and the amount of the illumination light irradiated from the lightsource, or sensitivity of the measurement portion is changed, it isdifficult to perform colorimetry with high accuracy. The change in thelight source or the measurement portion with time can be represented bya relative value on the basis of the standard white value based on themeasurement value of the standard white plate and the standard whitevalue that is the reference measurement value of the standard whiteplate.

Therefore, the correction portion corrects the measurement value of theevaluation patch based on the measurement value of the standard whiteplate and the standard white value that is the reference measurementvalue of the standard white plate so that the influence of a case wherethe light source or the measurement portion is changed with time isreduced. Therefore, even in a case where the light source or themeasurement position is changed with time, it is possible to performcolorimetry with high accuracy.

APPLICATION EXAMPLE 3

In the measuring device according to the application example, it ispreferable that the measuring device further includes a carriage onwhich the light source and the measurement portion are mounted, andwhich is movable relative to the measuring object, and the measurementvalue of the paper white patch and the measurement value of theevaluation patch are acquired while the carriage moves relative to themeasuring object.

Since the light source and the measurement portion are moved relative tothe measuring object together with the carriage, it is possible toefficiently perform colorimetry of the evaluation patch or the paperwhite patch formed on the measuring object compared to a case where thelight source, the measurement portion, and the carriage are separatelymoved relative to the measuring object.

APPLICATION EXAMPLE 4

In the measuring device according to the application example, it ispreferable that the measurement portion has a spectroscope and thespectroscope is a transmissive wavelength variable Fabry-Perot etalon.

As the spectroscope, if the transmissive wavelength variable Fabry-Perotetalon is used, it is possible to acquire a simple, compact, andinexpensive spectroscope.

APPLICATION EXAMPLE 5

In the measuring device according to the application example, it ispreferable that the storage portion holds the paper white standard valuefor each type of the measuring object.

Since the paper white standard value that is the reference measurementvalue of the paper white patch is different for each type of themeasuring object, it is preferable that the paper white standard valueis held in the storage portion for each type of the measuring object.

APPLICATION EXAMPLE 6

In the measuring device according to the application example, it ispreferable that the measuring object has a plurality of paper whitepatches, and the correction portion corrects the measurement value ofthe evaluation patch using the measurement value of the paper whitepatch positioned at a position close to the evaluation patch among theplurality of paper white patches.

If the paper white patch is positioned at a position away from theevaluation patch, in a case where cockling or the like occurs in themeasuring object, the measurement positions in the paper white patch andthe evaluation patch are different and there is a concern that theamount of received light in the paper white patch and the amount ofreceived light in the evaluation patch are different. Therefore, thereis a concern that it is difficult for the correction portion to performcorrection for reducing the influence of a case where the measurementposition of the evaluation patch is changed by the measurement value ofthe paper white patch that is at a position away from the evaluationpatch.

If the paper white patch is positioned at a position close to theevaluation patch, in a case where cockling or the like occurs in themeasuring object, the measurement positions in the paper white patch andthe evaluation patch are the same, and the amount of received light inthe paper white patch and the amount of received light of the evaluationpatch are substantially the same. Therefore, the correction portion canproperly perform the correction for reducing the influence of a casewhere the measurement position of the evaluation patch is changed by themeasurement value of the paper white patch that is at a position closeto the evaluation patch.

That is, it is preferable that the correction portion corrects themeasurement value of the evaluation patch using not the measurementvalue of the paper white patch positioned at a position away from theevaluation patch among the plurality of paper white patches but themeasurement value of the paper white patch positioned at a positionclose to the evaluation patch among the plurality of paper whitepatches.

APPLICATION EXAMPLE 7

In the measuring device according to the application example, it ispreferable that in a case where the plurality of paper white patches arepresent at positions close to the evaluation patch, the correctionportion corrects the measurement value of the evaluation patch using anaverage value of the measurement values of the plurality of paper whitepatches at positions close to the evaluation patch.

In a case where the plurality of paper white patches are present at thepositions close to the evaluation patch, if the average value of themeasurement values of the plurality of paper white patches which arepositioned at the positions close to the evaluation patch is used, it ispossible to faithfully monitor the influence of a case where themeasurement position of the evaluation patch is changed.

APPLICATION EXAMPLE 8

A measuring method according to this application example is a measuringmethod of a measuring device having a light source that irradiates ameasuring object having an evaluation patch and a paper white patch withan illumination light, a measurement portion that acquires an amount ofthe illumination light reflected by the measuring object as ameasurement value, a carriage on which the light source and themeasurement portion are mounted, and which is movable relative to themeasuring object, a storage portion that holds a paper white standardvalue, and a correction portion that corrects a measurement value of theevaluation patch, the method including acquiring a measurement value ofthe evaluation patch while the carriage moves relative to the measuringobject; acquiring a measurement value of the paper white patch while thecarriage moves relative to the measuring object; and correcting ameasurement value of the evaluation patch based on the measurement valueof the paper white patch and the paper white standard value.

If the light source and the measurement portion are moved relative tothe measuring object together with the carriage, it is possible toefficiently acquire the measurement value of the evaluation patch andthe measurement value of the paper white patch compared to a case wherethe light source, the measurement portion, and the carriage areseparately moved relative to the measuring object.

Furthermore, the correction portion performs correction based on themeasurement value of the paper white patch and the paper white standardvalue so that the influence of a case where the measurement position ofthe evaluation patch is changed is reduced, and it is possible toperform colorimetry with high accuracy.

APPLICATION EXAMPLE 9

In the measuring method of a measuring device according to theapplication example, it is preferable that the storage portion furtherholds a standard white value that is a reference measurement value of astandard white plate, and the method further including acquiring ameasurement value of the standard white plate, and correcting ameasurement value of the evaluation patch based on the measurement valueof the standard white plate and the standard white value.

The correction portion performs correction based on the measurementvalue of the standard white plate and the standard white value that isthe reference measurement value of the standard white plate so that theinfluence of a case where the light source or the measurement portion ischanged with time is reduced, and it is possible to perform colorimetrywith high accuracy.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanyingdrawings, wherein like numbers reference like elements.

FIG. 1 is a schematic view illustrating an outline of a printerincluding a measuring device according to an embodiment.

FIG. 2 is a block diagram illustrating a schematic configuration of theprinter.

FIG. 3 is block diagram illustrating a functional configuration of a CPUincluded in a control unit of the printer.

FIG. 4 is a sectional view illustrating a schematic configuration of aspectroscopic device included in a measurement portion of the measuringdevice according to the embodiment.

FIG. 5 is a schematic view of a test pattern printed on a medium.

FIG. 6 is a graph illustrating a relationship between a wavelength and areflectance of various media.

FIG. 7 is a graph illustrating a relationship between a color differenceacquired from a reflectance of an evaluation patch calculated byExpression (1) and a measurement position of the evaluation patch.

FIG. 8 is a graph illustrating a relationship between a color differenceacquired from a reflectance of the evaluation patch calculated byExpression (2) and a measurement position of the evaluation patch.

FIG. 9 is a graph illustrating a relationship between a color differenceacquired from a reflectance of an evaluation patch calculated byExpression (3) and a measurement position of the evaluation patch.

FIG. 10 is a process flow illustrating a measuring method according tothe embodiment.

FIG. 11 is a schematic view of another test pattern.

FIG. 12 is a schematic view of another test pattern.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, an embodiment of the invention will be described withreference to the drawings. Such an embodiment illustrates an aspect ofthe invention, does not limit the invention, and can be arbitrarychanged within the scope of the technical idea of the invention. Inaddition, in each of the following drawings, a scale of each layer oreach portion is sometimes different from an actual scale in order tomake each layer or each portion size recognizable on the drawing.

Embodiment Outline of Printer

FIG. 1 is a schematic view illustrating an outline of a printer(printing apparatus) including a measuring device according to anembodiment. FIG. 2 is a block diagram illustrating a schematicconfiguration of the printer. FIG. 3 is block diagram illustrating afunctional configuration of a CPU included in a control unit of theprinter.

First, an outline of a printer 10 including a measuring device 17according to the embodiment will be described with reference to FIGS. 1to 3.

As illustrated in FIG. 1, the printer 10 includes a supply unit 11, atransport unit 12, a carriage 13, a carriage moving unit 14, a lightsource portion 171, and a measurement portion 172 which are mounted onthe carriage 13, a standard white plate 30, and a control unit 15 (seeFIG. 2). Moreover, the light source portion 171, the measurement portion172, the standard white plate 30, and the control unit 15 are alsoconfiguration elements of the measuring device 17. That is, the printer10 includes the measuring device 17.

The printer 10 controls each of the units 11, 12, and 14, and thecarriage 13 based on print data input from, for example, an externaldevice 20 (see FIG. 2) such as a personal computer, and prints an imageon a medium 8 that is an example of a “measuring object”.

Moreover, the light source portion 171 is an example of a “lightsource”. In addition, details of the measuring device 17 will bedescribed below.

The supply unit 11 is a unit that supplies the medium 8 that is an imageforming object to an image forming position. The supply unit 11 includesa roll body 111 around which, for example, the medium 8 is wound, a rolldrive motor (not illustrated), a roll drive wheel train (notillustrated), and the like. Therefore, the roll drive motor is driven tobe rotated based on a command from the control unit 15 and a rotationalforce of the roll drive motor is transmitted to the roll body 111 viathe roll drive wheel train. Therefore, the roll body 111 is rotated andthe medium 8 wound around the roll body 111 is supplied in a Y direction(sub-scanning direction).

Any medium may be used as the medium 8, as long as the medium 8 is animage forming object and, for example, plain paper, a copy sheet,synthetic paper, coated paper, and various types of ink jet specialpaper, a transparent medium such as a PET film, vinyl chloride film, orthe like can be exemplified.

Moreover, in the embodiment, an example in which a paper surface woundaround the roll body 111 is supplied is illustrated, but the inventionis not limited to the example. For example, the medium 8 such as thepaper surface mounted on a tray or the like may be supplied by anyfeeding method such as supplying the medium 8 one by one by a roller orthe like.

In addition, in the following description, a direction in which themedium 8 is supplied by the supply unit 11 is referred to as a Ydirection, a direction orthogonal to the Y direction is referred to asan X direction (scanning direction), and a vertical direction orthogonalto the X direction and the Y direction is referred to as a Z direction.Furthermore, abase end side of an arrow indicating a direction in thedrawing is referred to as a (−) direction and a tip end side of thearrow is referred to as (+) direction.

The transport unit 12 transports the medium 8 supplied from the supplyunit 11 along the Y direction. The transport unit 12 is configured toinclude a transport roller 121, a driven roller (not illustrated) thatis driven by the transport roller 121 with the medium 8 interposedbetween the transport roller 121 and the driven roller, and a platen122.

If the drive force is transmitted from the transport motor (notillustrated) to the transport roller 121 and the transport motor isdriven by the control of the control unit 15, the transport roller 121is driven to be rotated by the rotational force and transports themedium 8 along the Y direction in a state where the medium 8 is in apinched state between the transport roller 121 and the driven roller. Inaddition, the platen 122 facing the carriage 13 is provided in adirection on a downstream side (side on a Y(+) direction) in the Ydirection of the transport roller 121.

A print portion 16 that prints an image on the medium 8, the lightsource portion 171, and the measurement portion 172 are mounted on thecarriage 13.

The carriage 13 is provided movably by the carriage moving unit 14 alongthe scanning direction (X direction) intersecting with the Y direction.In addition, the carriage 13 is connected to the control unit 15 by aflexible circuit 131 and a printing process (image forming process withrespect to the medium 8) is performed by the print portion 16 mounted onthe carriage 13 based on a command from the control unit 15. As will bedescribed in detail later, the light source portion 171 and themeasurement portion 172 perform spectroscopic measurement (colorimetry)while moving relative to the medium 8 together with the carriage 13.

The carriage moving unit 14 causes the carriage 13 to reciprocate in theX direction based on a command from the control unit 15.

The carriage moving unit 14 is configured to include, for example, acarriage guide shaft 141, a carriage motor 142, and a timing belt 143.

The carriage guide shaft 141 is disposed in the X direction and both endportions are fixed to, for example, a casing of the printer 10. Thecarriage motor 142 drives the timing belt 143. The timing belt 143 issupported substantially parallel to the carriage guide shaft 141 and apart of the carriage 13 is fixed thereto. Therefore, when the carriagemotor 142 is driven based on a command of the control unit 15, thetiming belt 143 is driven in forward and rearward direction, and thecarriage 13 fixed to the timing belt 143 is guided by the carriage guideshaft 141 to reciprocate.

The print portion 16 discharges ink at a portion facing the medium 8 onthe medium 8 separately and forms an image on the medium 8. Inkcartridges 161 corresponding to inks of a plurality of colors aredetachably mounted on the print portion 16 and ink is supplied from eachof the ink cartridges 161 to an ink tank (not illustrated) via a tube(not illustrated). In addition, nozzles (not illustrated) dischargingink droplets are provided on a lower surface (position facing the medium8) of the print portion 16 corresponding to each color. For example,piezoelectric elements are disposed in the nozzles, the ink dropletssupplied from the ink tank are discharged, the ink droplets are landedon the medium 8, and dots are formed by driving the piezoelectricelements.

The ink cartridges 161 are filled with inks of four colors of cyan (C),magenta (M), yellow (Y), and black (K), and the ink droplets of fourcolors of cyan (C), magenta (M), yellow (Y), and black (K) aredischarged from the nozzles.

Moreover, the number of the inks is not limited to four colors and maybe less than the four colors, or may be greater than the four colors.

As illustrated in FIG. 2, the control unit 15 is configured to includean I/F 151, a unit control circuit 152, a memory 153, and a CentralProcessing Unit (CPU) 154.

The I/F 151 inputs print data input from the external device 20 into theCPU 154.

The unit control circuit 152 includes a control circuit thatrespectively controls the supply unit 11, the transport unit 12, theprint portion 16, the light source portion 171, a wavelength variableinterference filter 5 (see FIG. 4), the measurement portion 172, and thecarriage moving unit 14, and controls an operation of each unit based ona command signal from the CPU 154. Moreover, the control circuit of eachunit is provided separately from the control unit 15 and may beconnected to the control unit 15.

The memory 153 stores various programs or various types of data forcontrolling the operation of the printer 10. The memory 153 is anexample of the “storage portion” and holds a paper white standard valuethat is a reference measurement value of paper white patches 72A, 72B,72C, 72D, and 72E (see FIG. 5) and a standard white value that is areference measurement value of the standard white plate 30.

In addition, there is a plurality of paper types constituting the medium8 and the memory 153 holds the paper white standard value for each typeof the medium 8.

Moreover, the paper white standard value is a reflectance of the paperwhite patches 72A, 72B, 72C, 72D, and 72E acquired in the referencemeasurement position.

The standard white value is a reflectance of the standard white plate 30acquired in the reference measurement position.

As illustrated in FIG. 3, the CPU 154 reads and executes variousprograms stored in the memory 153, and thereby functions as a scanningcontrol unit 154A, a print control unit 154B, a measurement control unit154C, a colorimetry unit 154D, a calibration unit 154E, and the like.

The scanning control unit 154A outputs a command signal for driving thesupply unit 11, the transport unit 12, and the carriage moving unit 14to the unit control circuit 152. Therefore, the unit control circuit 152drives the roll drive motor of the supply unit 11 and supplies themedium 8 to the transport unit 12. In addition, the unit control circuit152 drives the transport motor of the transport unit 12 to transport apredetermined region of the medium 8 to a position of the platen 122facing the carriage 13 in the Y direction. In addition, the unit controlcircuit 152 drives the carriage motor 142 of the carriage moving unit 14to move the carriage 13 in the X direction.

The print control unit 154B outputs a command signal for controlling theprint portion 16 to the unit control circuit 152 based on the printdata, for example, input from the external device 20. When the commandsignal is output from the print control unit 154B to the unit controlcircuit 152, the unit control circuit 152 outputs a print control signalto the print portion 16, drives the piezoelectric elements provided inthe nozzles, and discharges ink to the medium 8. Moreover, whenexecuting the print, the carriage 13 moves in the X direction,alternately repeats a dot forming operation for forming dots bydischarging ink from the print portion 16 during the movement thereofand a transport operation for transporting the medium 8 in the Ydirection, and prints an image constituted of a plurality of dots on themedium 8.

The measurement control unit 154C executes the spectroscopic measurement(colorimetry) in the measuring device 17.

Specifically, the measurement control unit 154C outputs a command signalfor controlling light sources 171A1 and 171B1 to the unit controlcircuit 152, and emits light from the light sources 171A1 and 171B1.Furthermore, the measurement control unit 154C reads a drive voltage toan electrostatic actuator 56 (see FIG. 4) with respect to a wavelengthof light transmitting the wavelength variable interference filter 5which is described later from V-λ data of the memory 153, and outputs acommand signal to the unit control circuit 152. Therefore, the unitcontrol circuit 152 applies the drive voltage instructed to thewavelength variable interference filter 5 and causes light of a desiredtransmission wavelength to transmit from the wavelength variableinterference filter 5.

Therefore, the measurement control unit 154C acquires the reflectance ofevaluation patches 71C, 71Y, 71R, and 71G (see FIG. 5), or the paperwhite patches 72A, 72B, 72C, 72D, and 72E, and stores a colorimetricresult in the memory 153 in association with a voltage (or wavelength ofthe light transmitting the wavelength variable interference filter 5corresponding to the voltage) applied to the electrostatic actuator 56.

The colorimetry unit 154D is an example of the “correction portion” andcorrects a reflectance with respect to each measurement wavelength basedon a measurement value with respect to the measurement wavelength andthe reference measurement value (paper white standard value and standardwhite value). Furthermore, the colorimetry unit 154D calculatesachromaticity (for example, an L* value, an a* value, and a b* value inL*a*b* color space) based on the corrected reflectance and stores thechromaticity in the memory 153.

The calibration unit 154E updates print profile data stored in thememory 153 based on the colorimetric result of the evaluation patches71C, 71Y, 71R, and 71G.

Outline of Measuring Device

FIG. 4 is a sectional view illustrating a schematic configuration of aspectroscopic device included in a measurement portion of the measuringdevice according to the embodiment.

Next, an outline of the measuring device 17 will be described withreference to FIGS. 2 and 4.

As illustrated in FIG. 2, the measuring device 17 has the light sourceportion 171 that irradiates the medium 8 with the illumination light,the measurement portion 172 that acquires an amount of a reflected light(measurement light) which is acquired by reflecting the illuminationlight on the medium 8 as a measurement value, the carriage 13 (seeFIG. 1) capable of moving the light source portion 171 and themeasurement portion 172 relative to the medium 8, the control unit 15(the memory 153 holding the paper white standard value that is thereference measurement value of the paper white patches 72A, 72B, 72C,72D, and 72E), and the standard white plate 30 (see FIG. 1).

The measuring device 17 performs colorimetry of the paper white patch 72and the evaluation patch 71. Specifically, the measuring device 17acquires a measurement value of the paper white patches 72A, 72B, 72C,72D, and 72E, and a measurement value of the evaluation patches 71C,71Y, 71R, and 71G while the light source portion 171 and the measurementportion 172 mounted on the carriage 13 are moved relative to the medium8.

In the measuring device 17, the light source portion 171 irradiates themedium 8 with the illumination light and the measurement portion 172receives the reflected light (measurement light) reflected by the medium8. A spectroscopic device 172A provided in the measurement portion 172is able to select a transmission wavelength based on the control of thecontrol unit 15. The measurement portion 172 performs the colorimetry ofthe medium 8 by measuring an amount of light of each wavelength invisible light.

Moreover, in the embodiment, the measuring device performs colorimetryaccording to a method (45/0° colorimetric system) of optical geometricconditions defined by a colorimetric standard (JIS Z 8722). That is, theillumination light from the light source portion 171 is incident on themeasuring device 17 at an angle (angle of 45°±2°) of 45° with respect toa normal of the medium 8 and light reflected in a normal direction(angle within 10° with respect to the normal direction) of the medium 8is received in the measurement portion 172. That is, an illuminationdirection in which the illumination light is directed toward the medium8 and the measuring direction in which the measurement light is directedto the measurement portion 172 are different.

The light source portion 171 includes the first light source portion171A and the second light source portion 171B. The first light sourceportion 171A, the second light source portion 171B, and the measurementportion 172 are disposed in the Y direction. Specifically, the firstlight source portion 171A is disposed on a side in the Y(+) directionwith respect to the measurement portion 172 and the second light sourceportion 171B is disposed on a side in the Y(−) direction with respect tothe measurement portion 172.

Furthermore, the first light source portion 171A, the second lightsource portion 171B, and the measurement portion 172 are the same inpositions in the Z direction.

The first light source portion 171A includes the light source 171A1 andan illumination optical member 171A2, and irradiates the medium 8 withlight at an angle of 45° with respect to the normal of the medium 8, forexample, directed from the side in the Y(+) direction to the side in theY(−) direction.

The second light source portion 171B includes the light source 171B1 andan illumination optical member 171B2, and irradiates the medium 8 withlight at an angle of 45° with respect to the normal of the medium 8, forexample, directed from the side in the Y(−) direction to the side in theY(+) direction.

The light sources 171A1 and 171B1 are members emitting the illuminationlight with which the medium 8 is irradiated. In order to reduce size andweight of the light sources 171A1 and 171B1, it is preferable to use aLED or a LD (semiconductor laser) for the light sources 171A1 and 171B1.

The illumination optical members 171A2 and 171B2 are optical membersthat determine an irradiation direction or an irradiation range of theillumination light irradiated from the light sources 171A1 and 171B1,and, for example, are constituted of optical members such as single or aplurality of apertures, lenses, mirrors, or the like. For example, asthe illumination optical members 171A2 and 171B2, a configuration, inwhich single or a plurality of apertures are provided and the medium 8is irradiated with the illumination light having a predetermined opticalpath diameter transmitting the apertures, or the like is exemplified. Inaddition, as the illumination optical member 171B2, a collimator lensmay be provided. In this case, the medium 8 is able to be irradiatedwith the parallel illumination light from the light source portion 171and even in a case where a position of the medium 8 is displaced in theZ direction, it is possible to suppress a change in size (spot diameter)of an illumination region on the medium 8.

In the embodiment, the medium 8 is irradiated with two illuminationlights by two light sources of the first light source portion 171A andthe second light source portion 171B, but one light source maybeprovided. Furthermore, a plurality of illumination lights may beacquired from one light source by a beam splitter such as a half mirror.

The measurement portion 172 is constituted by the spectroscopic device172A, a light receiving portion 172B, a light receiving optical member172C, and the like. In the measurement portion 172, light (measurementlight) reflected by the medium 8 is guided to the spectroscopic device172A by the light receiving optical member 172C and light having apredetermined wavelength spectrally separated by the spectroscopicdevice 172A is received by the light receiving portion 172B.

The light receiving optical member 172C is constituted by single or aplurality of optical members. As the optical members, for example,single or a plurality of apertures can be exemplified. The measurementlight reflected by a predetermined measuring region on the medium 8 canbe guided to the spectroscopic device 172A and the light receivingportion 172B by providing the apertures. In addition, as the opticalmember constituting the light receiving optical member 172C, forexample, a lens such as a condensing lens may be provided, or a bandpass filter may be provided. In a case where the band pass filter isprovided, it is possible to cut light (for example, light other than thevisible light) other than a desired measurement wavelength range.

As illustrated in FIG. 4, the spectroscopic device 172A includes acasing 6 and the wavelength variable interference filter 5(spectroscope) stored in an inside of the casing 6.

The wavelength variable interference filter 5 is an example of the“spectroscope” and is a wavelength variable Fabry-Perot etalon element(transmissive wavelength variable Fabry-Perot etalon). The wavelengthvariable interference filter 5 is disposed in the measurement portion172 in a state of being stored in the casing 6. Moreover, for example,the wavelength variable interference filter 5 may be directly disposedin the measurement portion 172.

The wavelength variable interference filter 5 includes a fixed substrate51 and a movable substrate 52 having light-transmitting property withrespect to the visible light, and the fixed substrate 51 and the movablesubstrate 52 are bonded together by a bonding film 53 to be integrallyconfigured. The fixed substrate 51 is provided with a first grooveportion 511 and a second groove portion 512 having a shallower groovedepth than that of the first groove portion 511 which are formed byetching. A fixed electrode 561 and a fixed reflection film 54 arerespectively provided in the first groove portion 511 and the secondgroove portion 512. The fixed reflection film 54 is formed by, forexample, a metal film such as Ag, an alloy film such as an Ag alloy, adielectric multilayer film in which a high reflection layer and a lowreflection layer are laminated, or a laminated body by laminating ametal film (alloy film) and a dielectric multilayer film.

The movable substrate 52 includes a movable portion 521 and a holdingportion 522 which is provided outside the movable portion 521 and holdsthe movable portion 521. A surface of the movable portion 521 facing thefixed substrate 51 is provided with a movable electrode 562 facing thefixed electrode 561 and a movable reflection film 55 facing the fixedreflection film 54. As the movable reflection film 55, a reflection filmhaving the same configuration as that of the fixed reflection film 54which is described above can be used. The holding portion 522 is adiagram that surrounds a periphery of the movable portion 521 and isformed to have a smaller thickness than that of the movable portion 521.

Therefore, in the wavelength variable interference filter 5, theelectrostatic actuator 56 is configured by the fixed electrode 561 andthe movable electrode 562, and it is possible to change a gap dimensionof a gap G between the fixed reflection film 54 and the movablereflection film 55 by applying a voltage to the electrostatic actuator56. In addition, an outer peripheral portion (region which does not facethe fixed substrate 51) of the movable substrate 52 is provided with aplurality of electrode pads 57 individually connected to the fixedelectrode 561 and the movable electrode 562.

The casing 6 includes a base 61 and a glass substrate 62. The base 61and the glass substrate 62 are bonded, for example, by alow-melting-point glass bonding or the like and thereby an accommodatingspace is formed therein and the wavelength variable interference filter5 is stored in the accommodating space.

The base 61 is constituted by, for example, laminating thin ceramicplates and has a recessed portion 611 capable of storing the wavelengthvariable interference filter 5. The wavelength variable interferencefilter 5 is fixed to, for example, a side surface of the recessedportion 611 of the base 61 by a fixing member 64. A bottom surface ofthe recessed portion 611 of the base 61 is provided with a lighttransmission hole 612 and is bonded to a cover glass 63 that covers thelight transmission hole 612.

In addition, the base 61 is provided with an inner terminal portion 613that is connected to the electrode pad 57 of the wavelength variableinterference filter 5, and the inner terminal portion 613 is connectedto an outer terminal portion 615 provided on an outside of the base 61via a conduction hole 614. The outer terminal portion 615 iselectrically connected to the control unit 15.

Returning to FIG. 2, the light receiving portion 172B is disposed on anoptical axis (on a straight line passing through center points of thereflection films 54 and 55) of the wavelength variable interferencefilter 5, receives light transmitting the wavelength variableinterference filter 5 in a light receiving region, and outputs adetection signal (current value) corresponding to an amount of receivedlight. Moreover, the detection signal output by the light receivingportion 172B is input into the control unit 15 via an I-V converter (notillustrated), an amplifier (not illustrated), and an AD converter (notillustrated).

Colorimetry by Measuring Device

In the printer 10, in a manufacturing factory, a test pattern is printedby the printer 10, the test pattern is read by a colorimeter or ascanner, reference color data (chromaticity (L* value, the a* value, andthe b* value in L*a*b* color space) of a reference color) is acquired,and the reference color data is registered in the memory 153.

That is, in a state where the reference color data is registered in thememory 153, the printer 10 is shipped from the manufacturing factory.

Furthermore, in the printer 10, on a user side, a test pattern 70 (seeFIG. 5) is printed on the medium 8 by the print portion 16, colorimetryof the test pattern 70 is performed by the measuring device 17, acolorimetric result (chromaticity of the test pattern 70) of the testpattern 70 by the measuring device 17 and the reference color data(chromaticity of the reference color) registered in the memory 153 inadvance are compared, and in a case where both are different from eachother, color correction (update of the print profile data) is performed.

Specifically, the measurement control unit 154C performs colorimetry ofthe test pattern 70, the colorimetric result of the test pattern 70 iscorrected so that the colorimetry unit 154D has a correct colorimetricvalue, the calibration unit 154E compares the colorimetric result(chromaticity of the test pattern 70) of the test pattern 70 and thereference color data (chromaticity of the reference color) registered inthe memory 153 in advance, and in a case where there is color unevenness(color deviation) in the test pattern 70 printed on the medium 8, colorcorrection (update of the print profile data) is performed. That is, theprinter 10 performs the color correction (update of the print profiledata) based on the colorimetric result of the measuring device 17 andthereby it is possible to form an image reproducing a desiredchromaticity of the user with high accuracy.

Therefore, in order for the printer 10 to reproduce a desiredchromaticity of the user with high accuracy, it is important that themeasuring device 17 accurately performs colorimetry of the test pattern70 and correct chromaticity is acquired. In the embodiment, themeasuring device 17 has an excellent configuration capable of accuratelyperforming the colorimetry of the test pattern 70 and acquiring acorrect chromaticity, and details thereof will be described below.

FIG. 5 is a schematic view of the test pattern printed on the medium.

As illustrated in FIG. 5, in the test pattern 70, the evaluation patches71C, 71Y, 71R, and 71G are formed. The evaluation patches 71C, 71Y, 71R,and 71G have respectively same shape and are formed in an island shape.The evaluation patches 71C, 71Y, 71R, and 71G are color patches(patches) of the reference color formed by discharging ink on the medium8 by the print portion 16. In the following description, the evaluationpatches 71C, 71Y, 71R, and 71G may be referred to as the evaluationpatch 71.

A color of the evaluation patch 71C is cyan (C) and, hereinafter, theevaluation patch 71C may be referred to as the evaluation patch 71C ofcyan. A color of the evaluation patch 71Y is yellow (Y) and,hereinafter, the evaluation patch 71Y may be referred to as theevaluation patch 71Y of yellow. A color of the evaluation patch 71R isorange (R) and, hereinafter, the evaluation patch 71R may be referred toas the evaluation patch 71R of orange. A color of the evaluation patch71G is green (G) and, hereinafter, the evaluation patch 71G may bereferred to as the evaluation patch 71G of green.

The paper white patches 72A, 72B, 72C, 72D, and 72E are not patchesformed by discharging ink from the print portion 16 on the medium 8 butare portions exposed by the medium 8, are patches for the colorimetry ofthe medium 8, and may have any shape, form, and color as long as it is aportion which is exposed by the medium 8.

In FIG. 5, the paper white patches 72A, 72B, 72C, 72D, and 72E are drawnas a patch shape with frame lines surrounding a region for the sake ofexplanation, but the frame lines are not essential and may be aso-called margins.

In addition, although it is described as “paper white”, the surface ofthe medium 8 does not need to be paper and the surface does not need tobe white. It is only necessary that the reflectance of the surface ofthe medium 8 that is the measuring object may be a portion capable ofbeing measured.

Hereinafter, the paper white patches 72A, 72B, 72C, 72D, and 72E may bereferred to as the paper white patch 72.

In the test pattern 70, the paper white patch 72A, the evaluation patch71C of cyan, the paper white patch 72B, the evaluation patch 71Y ofyellow, the paper white patch 72C, the evaluation patch 71R of orange,the paper white patch 72D, the evaluation patch 71G of green, and thepaper white patch 72E are sequentially disposed in the X direction. Thatis, the test pattern 70 has an arrangement of one row and one column inwhich the evaluation patch 71 and the paper white patch 72 arealternately disposed in the X direction.

The paper white patches 72A and 72B are the paper white patches 72 thatare adjacent to the evaluation patch 71C of cyan and are positioned atpositions close to the evaluation patch 71C of cyan. The paper whitepatches 72B and 72C are the paper white patches 72 that are adjacent tothe evaluation patch 71Y of yellow and are positioned at positions closeto the evaluation patch 71Y of yellow. The paper white patches 72C and72D are the paper white patches 72 that are adjacent to the evaluationpatch 71R of orange and are positioned at positions close to theevaluation patch 71R of orange. The paper white patches 72D and 72E arethe paper white patches 72 that are adjacent to the evaluation patch 71Gof green and are positioned at positions close to the evaluation patch71G of green.

FIG. 6 is a graph illustrating a relationship between a wavelength and areflectance of various media. Specifically, in FIG. 6, a relationshipbetween the wavelength and the reflectance with respect to the medium 8and the standard white plate 30 in a case of being constituted by apaper type X, a paper type Y, or a paper type Z is illustrated.

FIG. 7 is a graph illustrating a relationship between a color differenceacquired from a reflectance of an evaluation patch calculated byExpression (1) and a measurement position of the evaluation patch. Acolor difference ΔE in FIG. 7 is a difference between chromaticity ofthe evaluation patch 71 acquired by Expression (1) in the measurementposition and chromaticity of the evaluation patch 71 acquired byExpression (1) in “zero (reference position)”.

Moreover, the measurement position of the evaluation patch 71 is aposition (distance between the measurement portion 172 and theevaluation patch 71) of the evaluation patch 71 with respect to themeasurement portion 172 in the Z direction. In addition, in a case wherethe measurement position of the evaluation patch 71 is “zero”, it isindicated that the evaluation patch 71 is positioned at the referenceposition that is a reference of the evaluation.

Furthermore, since the light source portion 171 (first light sourceportion 171A and the second light source portion 171B) and themeasurement portion 172 are the same in position in the Z direction, theposition (distance between the light source portion 171 and theevaluation patch 71) of the evaluation patch 71 with respect to themeasurement portion 172 in the Z direction and the position of theevaluation patch 71 with respect to the light source portion 171 in theZ direction are the same. Therefore, the measurement position of theevaluation patch 71 is also the position of the evaluation patch 71 withrespect to the measurement portion 172 in the Z direction.

Furthermore, the position (distance between the measurement portion 172and the paper white patch 72) of the paper white patch 72 with respectto the measurement portion 172 in the Z direction and the position(distance between the light source portion 171 and the paper white patch72) of the paper white patch 72 with respect to the light source portion171 in the Z direction are referred to as the measurement positions ofthe paper white patch 72.

The medium 8 is constituted of an opaque member or a translucent member.As described above, as the medium 8, various paper types such as plainpaper, a copy sheet, synthetic paper, coated paper, and various types ofink jet special paper, a transparent medium such as a PET film, andvinyl chloride film, can be used.

The standard white plate 30 is made of, for example, barium sulfate,magnesium oxide, alumina, a fluorine-based resin, or the like.

As illustrated in FIG. 6, the reflectance of the standard white plate 30indicated by a solid line in the drawing is substantially 1 (100%) withrespect to a wavelength region. The reflectance of the medium 8 isdifferent depending on the paper type. The reflectance of the medium 8constituted of the paper type Y indicated by a broken line in thedrawing is lower than the reflectance of the standard white plate 30,the reflectance of the medium 8 constituted of the paper type Zindicated by a two-dotted chain line in the drawing is higher than thereflectance of the standard white plate 30, and the reflectance of themedium 8 constituted of the paper type X indicated by a one-dotted chainline in the drawing has a portion of which the reflectance is lower thanthe reflectance of the standard white plate 30 and the reflectance ishigher than the reflectance thereof.

In addition, if a difference between the reflectance of the medium 8 andthe reflectance of the standard white plate 30 is great, a difference ofchromaticity (color tone) between the medium 8 and the standard whiteplate 30 is great.

In the embodiment, the medium 8 constituted of the paper type Y is used.

In addition, since the paper white patch 72 is a portion exposed by themedium 8, the reflectance of the paper white patch 72 is the reflectanceof the medium 8.

For example, the reflectance of the evaluation patch 71 of which thecolorimetry is performed by the colorimetry unit 154D can be representedby Expression (1).

$\begin{matrix}{{{reflectance}\mspace{14mu} {of}\mspace{14mu} {evaluation}{\mspace{11mu} \;}{patch}} = {\frac{\begin{matrix}{{measurement}\mspace{14mu} {value}\mspace{14mu} {of}} \\{{evaluation}\mspace{14mu} {patch}}\end{matrix}}{{standard}\mspace{14mu} {white}\mspace{14mu} {value}} \times {standard}{\mspace{11mu} \;}{white}\mspace{14mu} {correction}\mspace{14mu} {data}}} & (1)\end{matrix}$

The standard white value in Expression (1) is the reflectance of thestandard white plate 30 acquired in the reference measurement positionand, for example, is registered in the memory 153 in advance in amanufacturing factory of the printer 10.

Standard white correction data in Expression (1) is a correction valueobtained by dividing the measurement value of the standard white plate30 by the standard white value. For example, in a case where the amountof light of the light sources 171A1 and 171B1, sensitivity of the lightreceiving portion 172B, or the like is changed due to a change with timeor contamination, there is a concern that the measurement value of theevaluation patch 71 is also changed. The standard white correction datais a correction value (calibration value) for correcting (calibrating)the measurement value of the evaluation patch 71 so as not to be changedeven in a case where the amount of light of the light sources 171A1 and171B1 or the sensitivity of the light receiving portion 172B is changed.

In general, the reflectance of the evaluation patch is not an absolutereflectance but is expressed as a relative value (relative value basedon the standard white value) obtained by dividing the measurement valueof the evaluation patch 71 by the standard white value.

In Expression (1), the reflectance of the evaluation patch 71 iscalculated by correcting the measurement value of the evaluation patchrepresented as a relative value based on the standard white value by thestandard white correction data. The reflectance of the evaluation patch71 calculated by Expression (1) is corrected by the standard whitecorrection data. Therefore, an influence of a case where the amount oflight of the light sources 171A1 and 171B1 or the sensitivity of thelight receiving portion 172B is changed is reduced, that is, aninfluence of a case where a colorimetry condition is changed is reduced.Therefore, it is possible to properly (accurately) acquire thereflectance of the evaluation patch 71 by Expression (1).

Meanwhile, as illustrated in FIG. 7, if the measurement position of theevaluation patch 71 is changed from “zero (reference position)”, thecolor difference ΔE acquired from the reflectance of the evaluationpatch 71 calculated by Expression (1) is increased (changed). That is,if the measurement position of the evaluation patch 71 is changed, thereflectance or the chromaticity of the evaluation patch 71 calculated byExpression (1) is changed. Therefore, it is difficult to accuratelycalculate the reflectance of the evaluation patch 71 and accuratelyacquire the chromaticity of the evaluation patch 71 by Expression (1).

The reason that it is difficult to accurately calculate the reflectanceof the evaluation patch 71 and accurately acquire the chromaticity ofthe evaluation patch 71 by Expression (1) is conceivable as follows.

For example, if cockling or the like occurs in the medium 8, since themeasurement position of the evaluation patch 71 is changed, the amountof the illumination light with which the evaluation patch 71 isirradiated from the light source portion 171 is reduced and the amountof the reflected light (measurement light) from the evaluation patch 71received by the measurement portion 172 is reduced.

The carriage 13 on which the light source portion 171 and themeasurement portion 172 are mounted is movable by the carriage guideshaft 141 in the X direction. For example, in a case where a part of thecarriage guide shaft 141 is deflected and the carriage 13 is displacedto the platen 122 side, or in a case where the carriage 13 is displacedin the Z direction due to vibration during the moving of the carriage13, similarly, the measurement position of the evaluation patch 71 ischanged. Therefore, similar to a case where cockling occurs in themedium 8, the amount of the illumination light with which the evaluationpatch 71 is irradiated or the amount of the reflected light from theevaluation patch 71 is reduced.

As described above, if the measurement position of the evaluation patch71 is changed, since the amount of the illumination light with which themedium 8 is irradiated, or the amount of the reflected light from themedium 8 is changed, the reflectance of the evaluation patch 71calculated by Expression (1) is changed, and it is difficult toaccurately calculate the reflectance of the evaluation patch 71 byExpression (1) and accurately acquire the chromaticity of the evaluationpatch 71.

The paper white patch is disposed close to the evaluation patch 71 andthereby the measurement position of the evaluation patch 71 and themeasurement position of the paper white patch 72 are similarly changed.Therefore, the reflectance of the evaluation patch 71 in a case wherethe measurement position is changed and the reflectance of the paperwhite patch 72 in a case where the measurement position is changed aresimilarly changed. Therefore, it is conceivable that the reflectance ofthe evaluation patch 71 in a case where the measurement position ischanged can be corrected by the change in the reflectance of the paperwhite patch 72 in a case where the measurement position is changed.

Therefore, it is conceivable that the reflectance of the evaluationpatch 71 can be accurately calculated and the chromaticity of theevaluation patch 71 can be accurately acquired by Expression (2).

$\begin{matrix}{{{refectance}\mspace{14mu} {of}\mspace{14mu} {evaluation}\mspace{14mu} {patch}} = {\left( {\frac{\begin{matrix}{{measurement}\mspace{14mu} {value}\mspace{14mu} {of}} \\{{evaluation}\mspace{14mu} {patch}}\end{matrix}}{{standard}{\mspace{11mu} \;}{white}\mspace{14mu} {value}} \times {standard}\mspace{14mu} {white}\mspace{14mu} {correction}\mspace{14mu} {data}} \right) \times \frac{{standard}\mspace{14mu} {white}\mspace{14mu} {value}}{{measurement}{\mspace{11mu} \;}{value}\mspace{14mu} {of}{\mspace{11mu} \;}{paper}\mspace{14mu} {white}{\mspace{11mu} \;}{patch}}}} & (2)\end{matrix}$

The change in the reflectance of the paper white patch 72 in a casewhere the measurement position is changed can be represented by arelative value obtained by dividing the relative value of themeasurement value (reflectance of the paper white patch 72 in themeasurement position) of the paper white patch 72 based on the standardwhite value (reflectance of the standard white plate 30 acquired in thereference measurement position), that is, the standard white value bythe measurement value of the paper white patch 72.

Therefore, in Expression (2), the reflectance of the evaluation patch 71is calculated by correcting the reflectance (reflectance calculated by amathematical expression in parentheses) calculated by Expression (1)with the relative value which is obtained by dividing the standard whitevalue by the measurement value of the paper white patch 72. In otherwords, in Expression (2), the relative value obtained by dividing thestandard white value by the measurement value of the paper white patch72 is a correction coefficient for correcting the change in thereflectance of the evaluation patch 71 in a case where the measurementposition is changed, and the reflectance of the evaluation patch 71calculated by Expression (1) is corrected by the correction coefficient.

FIG. 8 is a graph illustrating a relationship between a color differenceacquired from a reflectance of the evaluation patch calculated byExpression (2) and a measurement position of the evaluation patch.Moreover, the color difference ΔE in FIG. 8 is a difference between thechromaticity of the evaluation patch 71 acquired by Expression (2) inthe measurement position and the chromaticity of the evaluation patch 71acquired by Expression (1) in “zero (reference position)”.

As illustrated in FIG. 8, a change in the color difference ΔE in a casewhere the measurement position of the evaluation patch 71 is changed issmaller in the color difference ΔE acquired by Expression (2) than inthe color difference ΔE acquired by Expression (1) as illustrated inFIG. 7. That is, if Expression (1) is corrected by the change in thereflectance of the paper white patch 72 in a case where the measurementposition is changed, the change in the color difference ΔE of theevaluation patch 71 in a case where the measurement position is changedis small.

However, in FIG. 8, although the change in the color difference ΔE issmall, the color difference ΔE in which the measurement position is zero(reference position) is not zero and is deviated from zero. That is, ifthe reflectance of the evaluation patch 71 calculated by Expression (1)is corrected by Expression (2), the chromaticity of the evaluation patch71 is changed. As described above, in the correction by Expression (2),since the chromaticity of the evaluation patch 71 is changed, it isdifficult to accurately calculate the reflectance of the evaluationpatch 71 and accurately acquire the chromaticity of the evaluation patch71 by Expression (2).

The reason that it is difficult to accurately calculate the reflectanceof the evaluation patch 71 by Expression (2) and accurately acquire thechromaticity of the evaluation patch 71 is conceivable as follows.

In the printer 10, the ink droplets are discharged to pixelsconstituting the evaluation patch 71 and colored dots formed by the inkdroplets are formed in the pixels. Therefore, the pixels constitutingthe evaluation patch 71 are configured of a portion in which the coloreddots are disposed and a portion in which the colored dots are notdisposed. The portion in which the colored dots are not disposedcorresponds to a portion where the medium 8 is exposed so that thereflectance of the evaluation patch 71 receives the influence ofreflectance of the medium 8.

As described above, in the embodiment, since the medium is constitutedof the paper type Y, in the correction by Expression (2), it isconceivable that the difference in the reflectance between the medium 8(paper white patch 72) constituted by the paper type Y and the standardwhite plate (see FIG. 6), that is, the difference in the color tonebetween the medium 8 constituted by the paper type Y and the standardwhite plate 30 affects the chromaticity (or reflectance) of theevaluation patch 71, and the reflectance of the evaluation patch 71 isnot accurately calculated (corrected).

Therefore, in a case where the difference in the color tone between themedium 8 and the standard white plate is great, in the correction byExpression (2), it is conceivable that it is difficult to perform thecolorimetry of the evaluation patch 71 with high accuracy.

Therefore, in the embodiment, the reflectance of the evaluation patch 71in a case where the measurement position is changed is corrected byExpression (3) indicated below and the chromaticity or the colordifference ΔE of the evaluation patch 71 is acquired from thereflectance of the evaluation patch 71 calculated by Expression (3).

$\begin{matrix}{{{reflectance}{\mspace{11mu} \;}{of}\mspace{14mu} {evaluation}\mspace{14mu} {patch}} = {\left( {\frac{\begin{matrix}{{measurement}\mspace{14mu} {value}\mspace{14mu} {of}} \\{{evaluation}\mspace{14mu} {patch}}\end{matrix}}{{standard}\mspace{14mu} {white}\mspace{14mu} {value}} \times {standard}\mspace{14mu} {white}{\mspace{11mu} \;}{correction}\mspace{14mu} {data}} \right) \times \frac{{paper}{\mspace{11mu} \;}{white}{\mspace{11mu} \;}{standard}\mspace{14mu} {value}}{{measurement}{\mspace{11mu} \;}{value}\mspace{14mu} {of}\mspace{14mu} {paper}{\mspace{11mu} \;}{white}{\mspace{11mu} \;}{patch}}}} & (3)\end{matrix}$

The paper white standard value in Expression (3) is the reflectance ofthe paper white patch 72 acquired in the reference measurement position,that is, the reflectance of the medium 8 acquired at the referencemeasurement position and, for example, is acquired in advance in amanufacturing factory of the printer 10, and is registered in the memory153.

The change in the reflectance of the paper white patch 72 in a casewhere the measurement position is changed can be represented by therelative value of the measurement value (reflectance of the paper whitepatch 72 in the measurement position) of the paper white patch 72 basedon the paper white standard value (reflectance of the paper white patch72 acquired in the reference measurement position), that is, therelative value obtained by dividing the paper white standard value bythe measurement value of the paper white patch 72.

Therefore, in Expression (3), the reflectance of the evaluation patch 71is calculated by correcting the reflectance (reflectance calculated by amathematical expression in parentheses) calculated by Expression (1) bythe relative value obtained by dividing the paper white standard valueby the measurement value of the paper white patch 72. In other words, inExpression (3), the relative value obtained by dividing the paper whitestandard value by the measurement value of the paper white patch 72 is acorrection coefficient for correcting the change in the reflectance ofthe evaluation patch 71 in a case where the measurement position ischanged, and the reflectance of the evaluation patch 71 calculated byExpression (1) is corrected by the correction coefficient.

In Expression (3), the correction coefficient for correcting the changein the reflectance of the evaluation patch 71 in a case where themeasurement position is changed is represented only by the colorimetricvalue (paper white standard value and the measurement value of the paperwhite patch 72) of the paper white patch 72. Therefore, it isconceivable that the difference in the color tone between the medium 8and the standard white plate 30 hardly affects.

FIG. 9 is a graph illustrating a relationship between a color differenceacquired from the reflectance of the evaluation patch calculated byExpression (3) and the measurement position of the evaluation patch.Moreover, the color difference ΔE in FIG. 9 is a difference between thechromaticity of the evaluation patch 71 acquired by Expression (3) inthe measurement position and the chromaticity of the evaluation patch 71acquired by Expression (1) in “zero (reference position)”.

As illustrated in FIG. 9, the change in the color difference ΔE in acase where the measurement position of the evaluation patch 71 ischanged is smaller in the color difference ΔE acquired by Expression (3)than the color difference ΔE (see FIG. 7) acquired by Expression (1).That is, if Expression (1) is corrected by the change in the reflectanceof the paper white patch 72 in a case where the measurement position ischanged, the change in the color difference ΔE of the evaluation patch71 in a case where the measurement position is changed is small.

Furthermore, since the color difference ΔE is zero in which themeasurement position is zero (reference position), the chromaticity ofthe evaluation patch 71 acquired by Expression (3) in the referenceposition and the chromaticity of the evaluation patch 71 acquired byExpression (1) in the reference position are the same. That is, even ina case where the reflectance calculated by Expression (1) is correctedby Expression (3), the chromaticity of the evaluation patch 71 is notchanged.

As described above, in the correction by Expression (3), since the colortone of the paper white patch 72 (medium 8) does not affect, the changein the chromaticity of the evaluation patch 71 does not occur and thechange of the color difference ΔE of the evaluation patch 71 in a casewhere the measurement position is changed can be reduced.

Therefore, in a case where the measurement position of the evaluationpatch 71 is changed, or in a case where the color tone in the paperwhite patch 72 and the standard white plate 30 is different, it ispossible to accurately correct the reflectance of the evaluation patch71 and to accurately acquire the chromaticity of the evaluation patch 71by correcting the reflectance of the evaluation patch 71 by Expression(3).

Therefore, in the measuring device 17 according to the embodiment, it ispossible to execute the colorimetry with high accuracy by correcting themeasurement value of the evaluation patch 71 by Expression (3) based onthe measurement value of the paper white patch 72 and the paper whitestandard value.

In addition, in the printer 10, since the change in the measurementposition of the evaluation patch 71 is less than substantially ±0.2 mm,if the reflectance of the evaluation patch 71 is corrected by Expression(3), it is possible to control the color difference ΔE of a case wherethe measurement position of the evaluation patch 71 is changed in arange of substantially ±0.2 mm to less than 0.2 (see FIG. 9).Furthermore, if the color difference ΔE is controlled to less than 0.2,the chromaticity of the evaluation patch 71 acquired by the measuringdevice 17 and the reference color data registered in the memory 153 arecompared, and the color correction (update of the print profile data) isperformed in a case where both are different. Therefore, the printer 10is able to form an image reproducing a desired chromaticity of the userwith high accuracy.

That is, the printer 10 is able to form an image reproducing a desiredchromaticity of the user with high accuracy by correcting thereflectance of the evaluation patch 71 by Expression (3).

Furthermore, in the embodiment, as illustrated in Expression (3), inaddition to performing the correction of the measurement value of theevaluation patch 71 based on the measurement value of the paper whitepatch 72 and the paper white standard value, the correction of themeasurement value of the evaluation patch 71 is performed based on themeasurement value of the standard white plate 30 and the standard whitevalue. That is, in the embodiment, the measurement value (reflectance ofthe evaluation patch 71) of the evaluation patch 71 is corrected by thestandard white correction data for performing the correction of a casewhere the amount of light of the light sources 171A1 and 171B1, thesensitivity of the light receiving portion 172B, or the like is changed.

According to such a configuration, even in a case where the amount oflight of the light sources 171A1 and 171B1, the sensitivity of the lightreceiving portion 172B, or the like is changed, it is possible toaccurately calculate the reflectance of the evaluation patch 71 and toaccurately acquire the chromaticity of the evaluation patch 71.

Moreover, in a case where a use time of the light sources 171A1 and171B1, or the light receiving portion 172B is short and the change inthe amount of light of the light sources 171A1 and 171B1, thesensitivity of the light receiving portion 172B, or the like is small,the correction by the standard white correction data can be omitted fromExpression (3). That is, it is possible to accurately calculate thereflectance of the evaluation patch 71 and accurately acquire thechromaticity of the evaluation patch 71 by Expression (4) described asfollows.

$\begin{matrix}{{{reflectance}\mspace{14mu} {of}\mspace{14mu} {evaluation}{\mspace{11mu} \;}{patch}} = {\frac{\begin{matrix}{{{measurement}\mspace{14mu} {value}{\mspace{11mu} \;}{of}}{\mspace{11mu} \;}} \\{{evaluation}{\mspace{11mu} \;}{patch}}\end{matrix}}{{standard}{\mspace{11mu} \;}{white}\mspace{14mu} {value}} \times \frac{{paper}{\mspace{11mu} \;}{white}{\mspace{11mu} \;}{standard}{\mspace{11mu} \;}{value}}{{{measurement}\mspace{14mu} {value}\mspace{14mu} {of}\mspace{14mu} {paper}{\mspace{11mu} \;}{white}\mspace{14mu} {patch}}{\mspace{11mu} \mspace{11mu}}}}} & (4)\end{matrix}$

Measuring Method

FIG. 10 is a process flow illustrating a measuring method according tothe embodiment.

Next, the measuring method of the measuring device 17 according to theembodiment will be described with reference to FIG. 10.

As illustrated in FIG. 10, the measuring method of the measuring device17 according to the embodiment includes a step of performing thecolorimetry of the standard white plate 30 (step S1), a step ofperforming the colorimetry of the paper white patch 72A (step S2), astep of performing the colorimetry of the evaluation patch 71C of cyan(step S3), a step of performing the colorimetry of the paper white patch72B (step S4), a step of performing the colorimetry of the evaluationpatch 71Y of yellow (step S5), a step of performing the colorimetry ofthe paper white patch 72C (step S6), a step of performing thecolorimetry of the evaluation patch 71R of orange (step S7), a step ofperforming the colorimetry of the paper white patch 72D (step S8), astep of performing the colorimetry of the evaluation patch 71G of green(step S9), a step of performing the colorimetry of the paper white patch72E (step S10), and a step of correcting the measurement value of theevaluation patch 71 (step S11).

Moreover, step S1 is an example of the “step of acquiring themeasurement value of the standard white plate”. Steps S3, S5, S7, and S9are an example of the “step of acquiring the measurement value of theevaluation patch”. Steps S2, S4, S6, S8 and S10 are an example of the“step of acquiring the measurement value of the paper white patch”. StepS11 is an example of the “step of correcting the measurement value ofthe evaluation patch based on the measurement value of the paper whitepatch and the paper white standard value”, and is an example of the“step of correcting the measurement value of the evaluation patch basedon the measurement value of the standard white plate and the standardwhite value”.

In step S1, a worker sets the standard white plate 30 at a predeterminedposition (for example, on the platen 122), the light source portion 171irradiates the standard white plate 30 with the illumination light, thescanning control unit 154A moves the carriage 13 so that the measurementportion 172 can receive the reflected light from the standard whiteplate 30. Subsequently, the measurement control unit 154C performs thecolorimetry of the standard white plate 30 and stores the measurementvalue (reflectance of the standard white plate 30) of the standard whiteplate 30 in the memory 153.

In other words, step S1 is a calibration step of calibrating thecolorimetry condition so that the measurement value (reflectance of thestandard white plate 30 at the measurement position) of the standardwhite plate 30, the measurement value (reflectance of the evaluationpatch 71 at the measurement position) of the evaluation patch 71, or themeasurement value (reflectance of the paper white patch 72 at themeasurement position) of the paper white patch 72 is not changed in acase where the amount of light of the light sources 171A1 and 171B1, thesensitivity of the light receiving portion 172B, or the like is changed.The colorimetry unit 154D can properly correct the measurement value ofthe evaluation patch 71 by step S1 in step S11 which is described below.

For example, if the use time of the light sources 171A1 and 171B1, orthe light receiving portion 172B is short and the amount of light of thelight sources 171A1 and 171B1, or the sensitivity of the light receivingportion 172B is not changed, it is possible to omit step S1.

For example, a configuration, in which the standard white plate 30 isdisposed (fixed) in a predetermined region (for example, a maintenanceregion in which maintenance of the print portion 16 is performed) of theprinter 10, and the colorimetry of the standard white plate 30 isautomatically performed without manually setting the standard whiteplate 30 and performing the colorimetry of the standard white plate 30by a worker, may be provided.

Moreover, in the embodiment, the step of performing the colorimetry ofthe standard white plate 30 (step S1) is performed before the step ofperforming the colorimetry of the evaluation patch 71 (steps S3, S5, S7,and S9), or the step of performing the colorimetry of the paper whitepatch 72 (S2, S4, S6, S8, and S10), but the invention is not limitedthereto. For example, the step of performing the colorimetry of thestandard white plate 30 (step S1) may be performed after the step ofperforming the colorimetry of the evaluation patch 71 (steps S3, S5, S7,and S9), or the step of performing the colorimetry of the paper whitepatch 72 (S2, S4, S6, S8, and S10). In addition, the step of performingthe colorimetry of the standard white plate 30 (step S1) maybe performedbetween the step of performing the colorimetry of the evaluation patch71 (steps S3, S5, S7, and S9), and the step of performing thecolorimetry of the paper white patch 72 (S2, S4, S6, S8, and S10).

Subsequently, a worker removes the standard white plate 30 from apredetermined position and performs the colorimetry (step S2 to stepS10) of the evaluation patch 71 or the paper white patch 72. In thecolorimetry (step S2 to step S10) of the evaluation patch 71 or thepaper white patch 72, the scanning control unit 154A moves the carriage13 on the test pattern 70 (see FIG. 5) in the X direction, and themeasurement control unit 154C performs the colorimetry of the evaluationpatch 71 or the paper white patch 72.

Specifically, the carriage 13 is moved from the paper white patch 72A tothe paper white patch 72E, and sequentially performs the colorimetry ofthe paper white patch 72A, the evaluation patch 71C of cyan, the paperwhite patch 72B, the evaluation patch 71Y of yellow, the paper whitepatch 72C, the evaluation patch 71R of orange, the paper white patch72D, the evaluation patch 71G of green, and the paper white patch 72E inorder. That is, in the embodiment, the process (steps S3, S5, S7, andS9) of performing the colorimetry of the evaluation patch 71 and theprocess (steps S2, S4, S6, S8, and S10) of performing the colorimetry ofthe paper white patch 72 are alternately and continuously performed.

Moreover, the order of performing the colorimetry of the evaluationpatches 71C, 71Y, 71R, and 71G, or the order of performing thecolorimetry of the paper white patches 72A, 72B, 72C, 72D, and 72E isdetermined by a layout of the test pattern 70 or a moving method of thecarriage 13. Therefore, the order of performing the colorimetry of theevaluation patches 71C, 71Y, 71R, and 71G, or the order of performingthe colorimetry of the paper white patches 72A, 72B, 72C, 72D, and 72Eis arbitrary.

In step S2, the measurement control unit 154C performs the colorimetryof the paper white patch 72A and stores the measurement value(reflectance of the paper white patch 72A at the measurement position)of the paper white patch 72A in the memory 153.

In step S3, the measurement control unit 154C performs the colorimetryof the evaluation patch 71C of cyan and stores the measurement value(reflectance of the evaluation patch 71C of cyan at the measurementposition) of the evaluation patch 71C of cyan in the memory 153.

In step S4, the measurement control unit 154C performs the colorimetryof the paper white patch 72B and stores the measurement value(reflectance of the paper white patch 72B at the measurement position)of the paper white patch 72B in the memory 153.

In step S5, the measurement control unit 154C performs the colorimetryof the evaluation patch 71Y of yellow and stores the measurement value(reflectance of the evaluation patch 71Y of yellow at the measurementposition) of the evaluation patch 71Y of yellow in the memory 153.

In step S6, the measurement control unit 154C performs the colorimetryof the paper white patch 72C and stores the measurement value(reflectance of the paper white patch 72C at the measurement position)of the paper white patch 72C in the memory 153.

In step S7, the measurement control unit 154C performs the colorimetryof the evaluation patch 71R of orange and stores the measurement value(reflectance of the evaluation patch 71R of orange at the measurementposition) of the evaluation patch 71R of orange in the memory 153.

In step S8, the measurement control unit 154C performs the colorimetryof the paper white patch 72D and stores the measurement value(reflectance of the paper white patch 72D at the measurement position)of the paper white patch 72D in the memory 153.

In step S9, the measurement control unit 154C performs the colorimetryof the evaluation patch 71G of green and stores the measurement value(reflectance of the evaluation patch 71G of green at the measurementposition) of the evaluation patch 71G of green in the memory 153.

In step S10, the measurement control unit 154C performs the colorimetryof the paper white patch 72E and stores the measurement value(reflectance of the paper white patch 72E at the measurement position)of the paper white patch 72E in the memory 153.

In step S11, the colorimetry unit 154D corrects the measurement value ofthe evaluation patch 71 acquired insteps S3, S5, S7, and S9, andacquires accurate reflectance or accurate chromaticity of the evaluationpatch 71 based on the measurement value of the standard white plate 30that is acquired in step S1, the standard white value registered in thememory 153, the measurement value of the paper white patch 72 acquiredin steps S2, S4, S6, S8, and S10, and the paper white standard valueregistered in the memory 153.

In step S11, the colorimetry unit 154D corrects the measurement value ofthe evaluation patch 71C of cyan based on Expression (3) using themeasurement value of the paper white patches 72A and 72B adjacent to theevaluation patch 71C of cyan. In other words, the colorimetry unit 154Dcorrects the reflectance of the evaluation patch 71C of cyan andacquires the chromaticity of the evaluation patch 71C of cyan based onExpression (3) using the measurement value of the paper white patches72A and 72B positioned close to the evaluation patch 71C of cyan in acase where a plurality of paper white patches 72 are present.

For example, since the paper white patch 72E positioned away from theevaluation patch 71C of cyan is different in the measurement positionfrom the evaluation patch 71C of cyan, there is a concern that thereflectance of the paper white patch 72E positioned away from theevaluation patch 71C of cyan and the reflectance of the evaluation patch71C of cyan are different. On the other hand, since the paper whitepatches 72A and 72B positioned close to the evaluation patch 71C of cyanare substantially the same in the measurement position as the evaluationpatch 71C of cyan, the reflectance of the paper white patches 72A and72B positioned close to the evaluation patch 71C of cyan, and thereflectance of the evaluation patch 71C of cyan are substantially thesame.

Therefore, it is preferable that the colorimetry unit 154D corrects thereflectance of the evaluation patch 71C of cyan and acquires thechromaticity of the evaluation patch 71C of cyan based on Expression (3)using not the measurement value of the paper white patch 72E positionedaway from the evaluation patch 71C of cyan, but the measurement value ofthe paper white patches 72A and 72B positioned close to the evaluationpatch 71C of cyan in a case where the plurality of paper white patches72 are present.

For example, in a case where the measurement position of the paper whitepatch 72 is locally changed, a measurement value which is not preferablefor the correction of the reflectance of the evaluation patch 71C ofcyan may be included in one of the measurement values of a plurality ofpaper white patches 72A and 72B positioned close to the evaluation patch71C of cyan.

In this case, the colorimetry unit 154D can properly correct thereflectance of the evaluation patch 71C of cyan based on Expression (3)if the average value of the measurement values of the plurality of paperwhite patches 72A and 72B which are present is used compared to a casewhere one of the average values of the measurement values of theplurality of paper white patches 72A and 72B which are present is used.

In other words, a bad influence of a case where the measurement valuewhich is not preferable for correction of the reflectance of theevaluation patch 71C of cyan is included can be reduced by using theaverage value of the measurement values of the plurality of paper whitepatches 72A and 72B which are present compared to a case where one ofthe measurement values of the plurality of paper white patches 72A and72B is used.

Moreover, in a case where the change in the measurement position of thepaper white patch 72 is locally small and the measurement value which isnot preferable for correction of the reflectance of the evaluation patch71C of cyan is unlikely to be included in the measurement values of theplurality of paper white patches 72A and 72B, the reflectance of theevaluation patch 71C of cyan may be corrected based on Expression (3)using one of the measurement values of the plurality of paper whitepatches 72A and 72B which are present close to the evaluation patch 71Cof cyan.

That is, the colorimetry unit 154D may be configured to correct themeasurement value of the evaluation patch 71C of cyan based onExpression (3) using one of the measurement value of the paper whitepatch 72A and the measurement value of the paper white patch 72B.

Subsequently, in step S11, similar to a case where the measurement valueof the evaluation patch 71C of cyan is corrected, the colorimetry unit154D corrects the measurement value of the evaluation patch 71Y ofyellow based on Expression (3) using the measurement values of the paperwhite patches 72B and 72C positioned close to the evaluation patch 71Yof yellow among the plurality of paper white patches 72.

Subsequently, in step S11, similar to a case where the measurement valueof the evaluation patch 71C of cyan is corrected, the colorimetry unit154D corrects the measurement value of the evaluation patch 71R oforange based on Expression (3) using the measurement values of the paperwhite patches 72C and 72D positioned close to the evaluation patch 71Rof orange among the plurality of paper white patches 72.

Subsequently, in step S11, similar to a case where the measurement valueof the evaluation patch 71C of cyan is corrected, the colorimetry unit154D corrects the measurement value of the evaluation patch 71G of greenbased on Expression (3) using the measurement values of the paper whitepatches 72D and 72E positioned close to the evaluation patch 71G ofgreen among the plurality of paper white patches 72.

Furthermore, in step S11, the colorimetry unit 154D calculates the L*value, the a* value, and the b* value of the evaluation patch 71C ofcyan and acquires the chromaticity of the evaluation patch 71C of cyanfrom the reflectance of the corrected evaluation patch 71C of cyan.Subsequently, the colorimetry unit 154D calculates the L* value, the a*value, and the b* value of the evaluation patch 71Y of yellow andacquires the chromaticity of the evaluation patch 71Y of yellow from thereflectance of the corrected evaluation patch 71Y of yellow.Subsequently, the colorimetry unit 154D calculates the L* value, the a*value, and the b* value of the evaluation patch 71R of orange andacquires the chromaticity of the evaluation patch 71R of orange from thereflectance of the corrected evaluation patch 71R of orange.Subsequently, the colorimetry unit 154D calculates the L* value, the a*value, and the b* value of the evaluation patch 71G of green andacquires the chromaticity of the evaluation patch 71G of green from thereflectance of the corrected evaluation patch 71G of green.

Therefore, the calibration unit 154E compares the chromaticity of theevaluation patches 71C, 71Y, 71R, and 71G and the reference color dataregistered in the memory 153 in advance, determines whether or not colorunevenness (color deviation) is present in the reference colorcorresponding to the evaluation patches 71C, 71Y, 71R, and 71G, andupdates the print profile data in a case where unevenness (colordeviation) is present in the evaluation patches 71C, 71Y, 71R, and 71G.

According to the configuration, the printer 10 can form an imagereproducing a desired chromaticity of the user with high accuracy.

Other Test Patterns

FIGS. 11 and 12 are schematic views of other test patterns.

In FIGS. 11 and 12, reference numerals A1 to A18 are assigned to regions(paper white regions) in which paper white patches 72 are disposed, andreference numerals B1 to B18 are assigned to regions (evaluationregions) in which evaluation patches 71 are disposed. Furthermore, thepaper white regions A1 to A18 are referred to as a paper white region Aand the evaluation regions B1 to B18 are referred to as an evaluationregion B. In addition, one paper white patch 72 is disposed in one paperwhite region A and one evaluation patch 71 is disposed in one evaluationregion B.

Next, outlines of other test patterns 70B and 70A will be described withreference to FIGS. 11 and 12.

As illustrated in FIG. 11, the other test pattern 70B has an arrangementof four rows and four columns in which, the paper white region A (paperwhite patch 72) and the evaluation region B (evaluation patch 71) arealternately disposed in the X direction and the Y direction. On theother hand, the test pattern 70 described above has the arrangement ofone row and one column in which the paper white patch 72 and theevaluation patch 71 are alternately disposed in the X direction.

In the test pattern 70B, the paper white regions A1 to A5 and theevaluation regions B1 to B4 are alternately disposed in a first row inthe X direction, the paper white regions A6 to A9 and the evaluationregions B5 to B9 are alternately disposed in a second row in the Xdirection, the paper white regions A10 to A14 and the evaluation regionsB10 to B13 are alternately disposed in a third row in the X direction,and the paper white regions A15 to A18 and the evaluation regions B14 toB18 are alternately disposed in a fourth row in the X direction.

Therefore, a paper white patch 72An (not illustrated) is disposed in apaper white region An and an evaluation patch 71Bn (not illustrated) isdisposed in an evaluation region Bn.

Four paper white patches 72A2, 72A6, 72A7, and 72A11 are disposed atpositions close to the evaluation patch 71B6 disposed in the evaluationregion B6, and four paper white patches 72A4, 72A8, 72A9, and 72A13 aredisposed at positions close to the evaluation patch 71B8 disposed in theevaluation region B8.

On the other hand, in the test pattern 70, for example, two paper whitepatches 72A and 72B are disposed at positions close to the evaluationpatch 71C of cyan.

As described above, in the test pattern 70B, the number of the paperwhite patches 72 disposed at the positions close to the evaluation patch71 is greater than that of the test pattern 70.

If the paper white patch 72 is present at a measurement positiondifferent from the measurement position of the evaluation patch 71 amongthe plurality of paper white patches 72 disposed at the positions closeto the evaluation patch 71, the measurement value of the paper whitepatch 72 at the different measurement position is not preferable forcorrecting the measurement value of the evaluation patch 71. Inaddition, it is difficult to specify the position or the number of thepaper white patches 72 which are not preferable to correct themeasurement value of the evaluation patch 71.

Therefore, if the number of the paper white patches 72 disposed atpositions close to the evaluation patch 71 is increased and themeasurement value of the evaluation patch 71 is corrected by an averagevalue of the measurement values of the paper white patches 72 disposedat positions close to the evaluation patch 71, an influence of themeasurement value of the paper white patches 72 which are not preferableto correct the measurement value of the evaluation patch 71 is reducedand it is possible to more properly correct the measurement value of theevaluation patch 71 than a case where the number of the paper whitepatches 72 disposed at positions close to the evaluation patch 71 issmall.

As illustrated in FIG. 12, in the test pattern 70A, the evaluationregions B1 to B9 are disposed in a first row in the X direction inorder, the paper white regions A1 to A9 are disposed in a second row inthe X direction in order, the evaluation regions B10 to B18 are disposedin a third row in the X direction in order, and the paper white regionsA10 to A18 are disposed in a fourth row in the X direction in order.

The paper white patches 72 having the same configuration are disposed inthe paper white regions A1 to A9 of the second row and the paper whiteregions A10 to A18 of the fourth row. Therefore, the band-shaped paperwhite patches 72 elongated in the X direction are disposed in the secondrow and the fourth row in the test pattern 70A.

Therefore, a scanning control unit 154A moves a carriage 13 in the Xdirection and a measurement control unit 154C performs colorimetry ofthe band-shaped paper white patches 72 disposed in the paper whiteregions A1 to A9 of the second row, or the band-shaped paper whitepatches 72 disposed in the paper white regions A10 to A18 of the fourthrow. That is, in the test pattern 70A, the colorimetry of the paperwhite patch 72 is performed in a wide range and it is possible toacquire the measurement value of the averaged paper white patch 72compared to the test pattern 70 described above. As a result, it ispossible to reduce the influence of the paper white patch 72 which isnot preferable for correcting the measurement value of the evaluationpatch 71.

For example, in a case where variation of the measurement position ofthe paper white patch 72 is large in the X direction, it is preferablethat the shape of the paper white patch 72 is long in the X direction.In a case where variation of the measurement position of the paper whitepatch 72 is large in the Y direction, it is preferable that the shape ofthe paper white patch 72 is long in the Y direction.

The invention is not limited to the above-described embodiments, but canbe properly changed within a scope not contrary to the gist or idea ofthe invention which can be read from the appended claims and the entirespecification, and various modifications other than the above-describedembodiments are conceivable. Hereinafter, modification examples will bedescribed.

MODIFICATION EXAMPLE 1

In each of the embodiments, a configuration, in which the medium 8 is anopaque member or a translucent member and the light reflected by themedium 8 is incident on the measurement portion 172, is exemplified, butthe invention is not limited thereto. In a case where the medium 8 of atransparent member is measured, or in a case where a transmission lighttransmitting a translucent member is measured, the light source portion171 or the measurement portion 172 may be provided on a platen 122 side.However, in this case, it is necessary to have a configuration formoving the light source portion 171 or the measurement portion 172provided on the platen 122 side in the movement direction of thecarriage 13 together with the movement of the carriage 13.

MODIFICATION EXAMPLE 2

In the embodiments, as the wavelength variable interference filter 5, alight transmission-type wavelength variable interference filter 5, whichtransmits a light of wavelength corresponding to the gap G between thereflection films 54 and 55 from the incident light, is exemplified, butthe invention is not limited thereto. For example, a lightreflection-type wavelength variable interference filter, which reflectsa light of a wavelength corresponding to the gap G between thereflection films 54 and 55, may be used. In addition, a wavelengthvariable interference filter of another type may also be used.

In addition, as the spectroscope, the wavelength variable interferencefilter 5 is exemplified, but the invention is not limited thereto. Asthe spectroscope, for example, a grating, an AOTF, an LCTF, or the likemay be used.

MODIFICATION EXAMPLE 3

In the above-described embodiments, the printer 10 including themeasuring device 17 is exemplified, but the invention is not limitedthereto. For example, a measuring device that performs only thecolorimetry process with respect to the medium 8 maybe provided.Further, the measuring device of the invention may be incorporated in aquality inspection apparatus that performs quality inspection of aprinted matter which is manufactured in, for example, a manufacturingfactory, or the measuring device according to the invention may beincorporated in any apparatus.

What is claimed is:
 1. A measuring device that measures colors of anevaluation patch formed in a measuring object and a paper white patchwhich is a portion that the measuring object is exposed, the devicecomprising: a light source that irradiates the measuring object with anillumination light; a measurement portion that acquires an amount oflight from the measuring object as a measurement value; a storageportion that holds a paper white standard value that is a referencemeasurement value of the paper white patch; and a correction portionthat corrects the measurement value of the evaluation patch based on themeasurement value of the paper white patch and the paper white standardvalue.